1. Field of the Invention
The invention relates to certain 2-phenylpiperidine compounds, more particularly to certain 2-[2-hydroxy-4-(ZW-substituted)phenyl]piperidines of the formula ##STR3## or a pharmaceutically acceptable acid addition salt thereof, useful as CNS agents, especially as analgesics, antiemetic and antidiarrheal agents for use in mammals, including man, methods for their pharmaceutical compositions containing them and intermediates therefore.
2. Description of the Prior Art
Despite the current availability of a number of analgesic agents, the search for new and improved agents continues, thus pointing to the lack of an agent useful for the control of broad levels of pain and accompanied by a minimum of side-effects. The most commonly used agent, aspirin, is of no practical value for the control of severe pain and is known to exhibit various undesirable side-effects. Other, more potent analgesics such as d-propoxyphene, codeine, and morphine, possess addictive liability. The need for improved and potent analgesics is, therefore, evident.
More recently, great interest in cannabinol-type compounds as analgesic agents has been exhibited, see, for example, R. Mechoulam, Ed., "Marijuana Chemistry, Pharmacology, Metabolism and Clinical Effects", Academic Press, New York, N.Y., 1973; Mechoulam, et al., Chemical Reviews, 76, 75-112 (1976).
U.S. Pat. No. 4,147,872, issued Apr. 23, 1979, discloses a series of 3-[2-hydroxy-4-(substituted)phenyl]piperidine CNS agents of the formula ##STR4## where R.sup.2 and R.sup.3 have certain values in common with R.sub.2 and R.sub.3, respectively, as defined for the instant compounds of formula (I). The compounds of formula (II) are active analgesics, tranquilizers, sedatives and antianxiety agents for use in mammals, and/or as anticonvulsants, diuretics and antidiarrheal agents.
U.S. Pat. No. 4,306,097, issued Dec. 15, 1981, discloses 3-[2-hydroxy-4-(substituted)phenyl]cycloalkanol analgesic agents.